No, becoming an atheist does not cause someone to become a psychopath. Psychopathy is a complex personality disorder that is believed to have a combination of genetic, neurological, and environmental factors contributing to its development. It is not caused by changes in religious beliefs or lack thereof.
Being an atheist simply means that someone does not believe in the existence of gods or deities. It is a matter of personal belief or lack of belief in supernatural entities. Atheists, like individuals of any religious belief or non-belief, come from diverse backgrounds and have a wide range of personalities, moral values, and behaviors.
It is important to avoid making sweeping generalizations or assumptions about individuals based on their religious or non-religious beliefs. Psychopathy is a rare and complex personality disorder, and it is not associated with any particular religious or non-religious affiliation. The development of psychopathy is a multifaceted process that involves various genetic, environmental, and psychological factors that interact in complex ways.